Cranking device.



D. STEWART;

CRANKING DEVICE.

APPLICATION FILED JAN. 26. 19x4.

1 1 34,974. Patented Apr. 6, 1915.,

, Bessemer, in the county of ,reversal of s rrED STA S FATE i OFFlCE.

DAVID STEWART, or BnssnME'n, ALABAMA, ASSIGNOR or onnroua'rn 'ro HOWARD LAMAR, OF BIRMINGHAM, ALABAMA, AND ONE-FOURTH T0 THEODORE LAMAR AND ONE-FOURTH TO N. J. STUART, BOTH OF IBESSEMER,

ALABAMA;

CRAR'KING- DEVICE.

Specification of Letters Patent.

Application filed January 26, 1914. Serial No. 814,478. 7

To all whom it may concern Be it known that I, DAVID STEWART, a citizen of the United States, residing at Jefferson and State of Alabama, have invented certain new and useful Imprfvements in Cranking Devices, of which the following is a specification. 1

My invention relates devices for explosive engines, automobile engines.

My object is to provide a device of this character, so constructed that the sudden the engine from a premature explosion therein during'the cranking operation, cannot impart a backward rotation to the crank. H

Another object is to provide a device of this character so constructed that however suddenly or. powerfully the engine to which it is attached may be reversed, there will be no strain imposed upon any part of the device.

Another object is to provide a device so simple in its construction, and so' sure in its operation that it can be absolutely relied to safety cranking especially upon at all times.

average me'c'haniccan, tools and facilities, apply it to any auto- I A still further object is to provide a deviceof so few parts, and of such easy and cheap construction that the additional cost of attaching it to an automobile at the factory 'will' beinappreciable; and that an with his ordinary mobile.

Minor objects will appear in the subjoined description;

The invention consists in certain novel constructions and combinations of parts hereinafter described and claimed, reference being made to the accompanying drawings.

An important feature of my invention consistsin dividing the crank shaft into two section's'longitudinally movable to or from each cthenandj'each capable of independent rotation; 'andin providing these two sections of the shaft with a ratchet clutch composed of two members having cooperating ratchet faces, one member of the clutch being rigidly secured to each section of the shaft; the

ratchet face of one section of the clutch being .of greater diameter than the cooperating face of the other section of the clutch; and a pawl adapted to ride up over the pro frame shown in jecting teeth of the one section of the when the shaft is turned forwardly, and to engage said teeth and separate the two sections of the clutch when it is attempted to turn the shaft backwardly.

Referring to the drawlngs, Figure 1 is a perspective view of my device detached from the engine.

is a perspective of the'pawlemployed for Batented Apr. 6,1915. 9

clutch dotted lines; and Fig. 4

separating the two members of the clutch.

The numeral 1 indicates a suitable supporting frame, provided with openings 2 for securing the device to the automobile. The frame is also provided with the bores 3 and 4: at its inner and outer ends respectively, into which bores are received the two respective sections "5 and 6 of the divided shaft. The section 6 of the divided shaft is providedat its outer end with a squared section 7 for receiving a suitable crank, and at its inner end with a central longitudinal bore 8 into which is loosely received the outer end of the other section ofthe shaft. The section 9 of the ratchet clutch is integrally secured to the'section 6 of the shaft at its inner end, and the cooperating section 10 of the clutch'is rigidly secured to the other section' (5) oftheshaft by means of the pin 11 which passes through registering bores 12 and 13 in said clutch section 10 .and shaft secti0n5.

The collar 14 is rigidly secured to the shaft section 5 just outside the frame 1 by means of the set screw 15; and the collar 16 fills the space between the inside of the frame and the clutch section 10, by which means the shaft section 5 carrying the clutch section '10 is held against longitudinal movement in the frame 1'.. But the outer shaft section 6 has its bore 8 of sufficient depth and its clutch section 9 sufficiently spaced inwardly froiiithe inner face of the forward end of the frame 1 to permit said section 6 to have a limited longitudinal movement on said frame, whereby to permit the clutch section 9 to be moved into and out of engag'ement with its tion 10 on the other section of the divided cooperating clutch secthe outer section 6 of the divided shaft, I provide the collar 17 which has the integral \flange 18, by means of which it is rigidly ,tion, the inclination of the cooperating teeth "ofthe two sections being arranged for rotation in this direction. It will, however, be oticed that the ratchet face of the clutch ection 9 is of greater diameter than the cooperating ratchet face of the section 10, and this constitutes a very-important feature .of my invention, as will presently appear.

The frame I of my device is provided with an integral projection 22 having a suitable recess 23 in which is pivoted at its outer end the pawl 24 pressed by the spring 25. The two sections 9 and 10 of the clutch are of greaterdiameter than their respective ratchet faces so as to provide said sections with the annular shoulders 26 and 27 respectively. Extendin inwardly from the base of the shoulder 2 ofthe clutch section 10, is a collar 28 on the inner edge of which the series of clutch teeth 21 are formed with a space remaining between the roots of the teeth and said shoulder. The free end of the spring-pressed ratchet 24 is easily received between the two shoulders 26 and 27 of the clutch sections 9 and 10. This ratchet 2-l at its forward end on its side next the projecting ratchet teeth 20 is provided with an inclined face 29 adapted to cooperate with-the inclined sides of said projecting ratchet teeth, Whenever it is attempted to reverse'the rotation of the clutch member 9. It will be noticed that this face 29 is so inclined as to project outwardly at its bottom so that when the clutch section 9 is turned backwardly the action of the teeth 20 upon this face will impart a downwardtendency to the ratchetand thus assist the spring 25 in insuring that the end of the pawlshall pothfiy up out of engagement with said eet I When backfiring of the engine takes place and starts to'turn'the clutch section 9 with its shaft section 6 backward, this face 29 of the pawl 24, engages the first one of the projectingteeth 20' that reaches it and instantly shunts the clutch section 9 out of engagement with its cooperating section 10, and thus prevents a backward rotation of the shaft section 6 which carries the operating crank. This leaves the section 5 of the shaft with its clutch section 10 free to conmsaem tinue its backward rotation without interference. I

In order to increase the downward tendency of the free end of the pawl 24 when its inclined face 29 is engaged by the projecting teeth 20 of the clutch section 9, I have provided the radial edges of said teeth with a slight inward inclination from their outer ends to their inner ends and in order to make the cooperating teeth 21 of the section 10 correspond to these, their inner edges are correspondingly inclined outwardly from their outer ends to their inner ends; that is to say, in general contour, the one ratchet face is con cave and the other is correspondingly convex. During the backward rotation of the clutch section 10 the extreme forward tapered end 30 of the pawl 24 rides upon the collar 28 ofsaid clutch section. The shoulders 26 and 27 of the two clutch sections guard the free end of the pawl against lateral movement or strain.

The projection 22 of the frame 1 carries a pin 31 which forms a positive stop for limiting the upward movement of the awl 24, to prevent the free end of the pawl rom rising upwardly beyond the shoulders 26 and27 of the clutch. This keeps the pawl from ever being moved or jolted out of operative relation to the teeth 20 and will always hold it in position to reliably operate by gravity even though the spring 25 should be broken or dispensed with.

When it is attem ted to reverse the rotation of clutch section 9, the forward end 30 of the pawl is simply wedged between the shoulder 27 of the clutch section 10 and the projecting teeth 20 of the section 9 as they engage it on its face 29. In this way the pawl operates with the power of a wedge to force the two section-s 9 and 10 of the clutch apart out of engagement with each other. And as only comparatively slight power is actually required for this operation, the pawl does its work with great ease and promptness, and freedom from strain or jar to any of the parts. When the clutch is rotated forwardly, the free end of the pawl simply rides up over the outer peripheral ends of the projecting teeth 20 of the clutch section 9.

In operation the crank is placed on the squared end 7 of the shaft section 6, which section is then pushed inwardly as it is rotated to cause the two sections 9 and 10 of the clutch to firmly engage each other. The

shaft is then rotated forwardly in the usual manner. When .thus rotated the pawl 24 rides up over the outer ends of the project mg teeth 20, but if a premature explosion takes place and suddenly reverses the rotation of the shaft section 5 and its clutch section 10, the inclined face 29 of the pawl 24 engages the projecting teeth 20 and throws the section 9 of the clutch out of engagement when the most sudden and violent reversal,

with the section 10, which prevents the section 5 of the shaft from imparting rotation to the outer section 6 thereof which carries the crank.

In view of the construction set forth, special attention is called to the fact that of the engine takes place, there is no strain placed upon any part of my device, and the parts are so few and reliable that theoost of manufacture is reduced to a minimum, and

under ordinary circumstances there is practically nothing to get out of order. Moreover the device is capable of being readily applied to any automobile. These features of the device, taken in connection with its thoroughly satisfactory operation, give it 1 great value from a practical point of view.

Having thus described my invention, what I I claim as new and desire to'secure by Letters Patent is 1. In cranking devices for explosive en-v gines, the combination with cooperating clutch members provided wi h opposing faces having radial teeth adapted to engage each other, one of said faces projecting beyond the other; of a pawl disposed at a tangent to said clutch members and adapted,

when the clutch is turned in its forward direction, to ride up over the peripheral ends of the teeth of the projecting clutch member, and when it is turned in its backward direction, to engage the radial faces of the same teeth and force said clutch members apart.

2. Ina device of the character described, v

the combination with cooperating clutch members having opposing circular faces provided with radially disposed ratchet teeth adapted to interlock with each other when the clutch is rotated in its forward direction, one of said interlocking ratchet "faces projecting radially beyond the other,

of a stationary pawl having its free end resting upon the peripheral ends of said projecting ratchet teeth and adapted to ride up over said teeth when the clutch is rotated in its forward direction, and to directly engage their inclined radially disposed faces and force the one clutch member out of engagement with the other when the clutch is turned backward.

3. In a device of the character described, the combinationof opposin clutch members having complementary ratc et faces formed on their opposing sides, one of said ratchet faces projecting radially beyond the other; the clutch member having the greater ratchet face being movable into and out of engagement with the cooperating member having the smaller ratchet face, and said latter clutch member being provided with an annular shoulder of greater diameter than the ratchet face and a stationary pawl having its free end resting upon the peripheral ends of said projecting ratchet teeth and adapted to ride up over said teeth when clutch is rotated backward.

' the combination 4. In a devicepfthe character described,

' "of opposing; circular clutch members having complementary ratchet faces formed on their opposing s1des,'sa1d members being of greater diameter than 7 their ratchet faces to provide each clutch member with anannular shoulder, and one of said ratchet faces projecting radially beyond the other; a stationary pawl d sposed at a tangent to the-clutch and having its free end arranged to extend in between the .85 annular shoulders of the two members thereof, and of a width to be received between said shoulders, and adapted to rest upon and ride up over the peripheral ends of said projectlng ratchet teeth when the clutch v is rotated forwardly, and to dro in between the inclined faces of said pro ecting teethv and the annular shoulder of the opposin clutch section when the clutch is rotate backwardly to force the clutch members out of engagement with each other; an annular bearing on said opposing clutch member to limit the downward movement of the free end ofthe pawl; and means for utilizin the action of the ratchet teeth upon the paw 'tation of the clutch.

5. In-adevice of the character described, the combination of two. circular clutch mem bers having opposing faces provided with cooperating ratchet teeth, said members alsg; having annular shoulders of greater diani' eter than the clutch faces, one of said clutch faces extending radially beyond the other; a' stationary pawl arranged at a tangent to. the clutch and having its free end arranged to extend in between the shoulders of the clutch members to directly engage the teeth of the projecting ratchet face to forcesaid clutch members apart; and a stop for the pawl to prevent the free end thereof from moving upwardly beyond the periphery of said annular shoulders of the opposing clutch members. r j

6; In a device of the character described, the combination with a ratchet wheel having one of its faces provided with ratchet teeth and adapted to be shunted laterally, of a pawl adapted to engage the inclined faces of the ratchet teeth to shunt the wheel, said pawl being provided at its free end with a face inclined from front to rear to correspond with the inclination of the'inclined. 18.0

faces of the ratchet teeth to be engaged by In testimon whereof IaifiX my signature it, said face being also inclined inwardly in presence 0 two witnesses.

from its bottom to its top to form an acute u DAVID STEVART angle with the bottom of the pawl, to cause the lower edge of said face to be the first Witnesses:

"\part engaged by the inclined faces of the THEO. J. LAMAR,

said ratchet teeth as they contact With it. \V. H. SNOW.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. C. 

